Superpower is needed for Blissey and Tyranitar. Earthquake doesn't hit anything Fire Blast can't off the top of my head.
With Life Orb, Sand, Roost, Stealth Rock, multiscale loses a lot of luster. Superpower is way too good, and Mixed Dragonite is very underatted just because it can't run multiscale.
Yes, run Recover/Hydro Pump/Ice Beam/Hidden Power Grass.